Journal of King Saud University - Science最新文献

Polystyrene microplastics (PS-MPs) are environmental toxicants that exert adverse effects on organisms. Rhamnetin (RHM) is a natural flavone that shows multiple therapeutic potentials. Therefore, the present study was planned to determine the mitigative effect of RHM against PS-MPs induced liver damage. 48 rats were divided into 4 groups. Control group, PS-MPs (0.01 mg/kg) administered group, PS-MPs (0.01 mg/kg)+ RHM (50 mg/kg) co-administered group and RHM alone (50 mg/kg) administered group. PS-MPs reduced the expressions of Nrf-2 and anti-oxidant gene expressions, while increasing Keap-1 expression. PS-MPs also decreased the activities of catalase (CAT), glutathione reductase (GSR), heme oxygenase-1 (HO-1), glutathione-S-transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH), besides elevating the levels of MDA and ROS. Additionally, PS-MPs augmented the levels of alanine transaminase (ALT), alkaline phosphatase (ALP) and aspartate aminotransferase (AST). Furthermore, there was an upsurge in the levels of inflammatory indices in PS-MPs treated group. PS-MPs intoxication also increased Bax and Caspase-3 expressions, while lowering the Bcl-2 expression. Nevertheless, RHM mitigated all the damages due to its hepatoprotective, anti-inflammatory, anti-oxidant and anti-apoptotic potentials.

Polystyrene microplastics (PS-MPs) are raising global concerns as they have tendency to induce adverse effects on organisms. Herbacetin (HBN) is a natural flavone that shows diverse biological activities. Therefore, the current study was designed to evaluate the curative role of HBN against PS-MPs provoked hepatic damage. Forty-eight rats were divided into 4 groups, control, PS-MPs-intoxicated (0.01 mg/kg), PS-MPs + HBN co-treated (0.01 mg/kg + 40 mg/kg) and HBN only treated (40 mg/kg) group. The experiment was conducted for 30 days. PS-MPs administration reduced the expressions of Nrf-2 as well as anti-oxidants genes and increased Keap-1 expression. It also lessened the activities of superoxide dismutase (SOD), glutathione reductase (GSR), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and heme oxygenase-1 (HO-1) and glutathione (GSH) level, while elevating the levels of MDA and ROS. Additionally, PS-MPs exposure augmented the levels of alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine transaminase (ALT). Furthermore, there was an upsurge in the levels of inflammatory indices in PS-MPs treated group. PS-MPs also upregulated Caspase-3 and Bax expression whereas, decreased Bcl-2 expression. Nevertheless, HBN treatment recovered all the impairments due to its anti-apoptotic, anti-oxidant and anti-inflammatory and hepatoprotective nature. Therefore, it is deduced that HBN could be used as a potential therapeutic agent to counter PS-MPs induced hepatic toxicity.

Background

The changes in land use patterns may provide immediate economic advantages, but they also lead to significant disruptions in ecosystem services. These modifications have the potential to adversely impact water supply, air quality, disaster response, carbon storage, and biodiversity. Therefore, these modifications affect the provision of ecosystem services and have a negative effect on human well-being. Hence, it is crucial to investigate how land use changes affect carbon storage to enhance ecosystem services, lessen the consequences of climate change, advance human welfare, and direct effective land management practices.

Methods

Min River Basin (MRB) is a significant water reservoir in China, providing valuable ecosystem services. Currently, the MRB is undergoing significant alterations in the land use due to country’s policy changes. Therefore, this study analyzed alterations in land use, dynamics of the alterations, and transfer matrix in MRB. The alterations in these indices were recorded for three time periods, i.e., 2000, 2010, and 2020. Furthermore, the influence of land use changes on carbon storage was investigated by InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model.

Results

The main land use classes in the MRB consisted of forest land, grassland, and arable land, and most of the alterations were recorded among these three classes. The arable land was declined by 163–333 km², while grassland reduced by 23–233 km² from 2000 to 2020. Likewise, forest land witnessed a decrease of 34–167 km² from 2000 to 2020. The dominant land use dynamics consisted of construction land and water areas, whereas the entire land use dynamics exhibit a consistent increasing trend. Moreover, carbon storage witnessed a significant decrease during the study period due to the reduction in forest land, grassland, and arable land.

Conclusion

The land use patterns in the MRB have witnessed substantial transformations because of recent policy implementations. Land use changes from forest land, arable land and grassland to other types exerted significant influence on carbon storage. Generally, carbon storage decreased from 2000 to 2020. The decline in carbon storage in the MRB is mostly attributed to urban growth, and construction activities. Therefore, these activities should be carefully monitored to improve carbon storage in the basin.

Objectives

This study aimed to characterize Aeromonas veronii CTe-01 focusing on its resistance to heavy metal and antibiotics.

Methods

A. veronii CTe-01 was characterized using standard microbiological and molecular techniques. Antibiotic susceptibility and heavy metal resistance were tested per standard protocols. Genomic analysis, including plasmid characterization, was conducted in silico.

Results

A. veronii CTe-01 showed resistance to various heavy metals and antibiotics. Multiple resistance genes were identified, including those for beta-lactamases, heavy metal resistance, and type III secretion system components. The bacterium carries a 9 kb plasmid with repA/repB replication genes, parA/parB partitioning genes, and a type II toxin-antitoxin system for stability.

Conclusions

A. veronii CTe-01 is a genetic reservoir for antibiotic resistance, heavy metal resistance genes, and virulence factors. The study offers insights into its dual role as a pathogen and heavy metal remediator in aquatic environments.

Background

Metallo-β-lactamases (MBLs) type carbapenemases are produced by pathogenic Pseudomonas spp. and exhibit carbapenemase activity. The study will look into drug resistance and the molecular mechanisms of drug-resistant Pseudomonas aeruginosa variants.

Methods

A total of 74 P. aeruginosa strains were isolated from urine, pus, sputum, blood, throat swab, Foley’s catheter, and nasal swab. The isolates were screened for antibiotic susceptibility and the identified MDR strains were further tested for β-lactamase production. Multiplex PCR was used to identify the presence of mcr-1 and blaNDM-1 genes in MDR organisms. The minimum inhibitory concentration for ceftazidime and colistin was also determined, in addition to the biofilm inhibitor activity. Confocal microscopy was used to determine the production of biofilms.

Results

The isolated P. aeruginosa strains exhibited antibiotic resistance to aminoglycosides (amikacin and gentamicin). Fifty three percent of the isolated P. aeruginosa strains produced metallo-β-lactamase and the remaining isolates were non-metallo-β-lactamase type (46.8 %) (p < 0.0001). The MIC value of β-lactamase producers against colistin ranges from 0.5 µg/mL to 6 µg/mL. The MDR bacteria exhibited mcr-1 and blaNDM−1 genes. The MDR P. aeruginosa strain treated with colistin and ceftazidime inhibited initial biofilm formation. These combination of antibiotics effectively prevented initial biofilm development than individual antibiotics (p < 0.001).

Conclusions

The current analysis detected MDR among P. aeruginosa isolates that carried drug-resistant genes.

An important contributing factor to the growth of aggressive and treatment-resistant tumors is tumor hypoxia. In this investigation, we created a unique tracer, ⁶⁴Cu-biacetyl-bis(4-methyl-3-semicarbazone) Complex (⁶⁴Cu-[APSC]₂), for hypoxia imaging. Numerous spectral and electrochemical analyses were used to characterize the synthesized ligand and its metal complex. The coordination of the metal in the metal complex was also supported by DFT (B3LYP model) calculations. The radiochemical yields and purities of ⁶⁴Cu-[APSC]₂ were found to be quantitative, as determined by TLC and HPLC analyses.

Stability studies in human plasma demonstrated that ⁶⁴Cu-[APSC]₂ remained steady for at least four hours while being incubated at 37 °C. MDA-MB-231 cell-line xenografts were placed in nude mice for biodistribution research. The results revealed significant accumulation of the tracer in tumors after 2 h post-injection, which correlated with the redox potential and reactive oxygen species. These findings suggest that ⁶⁴Cu-[APSC]₂ shows promising evidence as a theranostic radiopharmaceutical for hypoxic tumors.

This study was carried out to explore the significance of morphology-based selection for breeding, using a case study of indigenous buckwheat landrace from Korea. Although many studies have utilized molecular methods to investigate germplasm diversity, this research underscores the often-overlooked importance of morphology-based selection in breeding strategies. Furthermore, it highlights the necessity of considering geographical information only when it accurately reflects the actual environment. The study collected and analyzed five traits from 96 samples across 27 varieties. The hypothesis was that these 27 samples might have been grouped by region due to similar environmental conditions. This hypothesis was tested using a dendrogram, clustering, correlation analysis of each trait, and PCA analysis. The results showed that morphological traits are a crucial factor in germplasm or landrace selection and that they should be considered the basic information for breeding purposes. Morphological traits were found to be random regardless of the locations where they were collected, indicating that they should be used to determine breeding targets rather than geographic locations. The study suggested that understanding the physiological traits of specific germplasm groups can accelerate breeding efforts. Overall, this study provided important insights into the selection of germplasm or landrace for breeding purposes, highlighting the importance of morphology-based selection and the need to consider environmental factors.

Background

The coffee plant is a strategic crop in Saudi Arabia that makes a substantial contribution to the country’s economy. Therefore, it is crucial to continuously monitor and control the fungal phytopathogens that affect coffee plants in order to minimize crop losses and ensure sustainable cultivation. This is the first surveillance report of Fusarium phytopathogens associated with coffee plants in Saudi Arabia. Moreover, the antagonistic efficiency of the endophytic fungus, Diaporthe caatingaensis, was evaluated against the isolated Fusarium phytopathogens.

Methods

The isolated strains were preliminary identified using cultural and microscopic methods and the identification was confirmed using internal transcribed spacer (ITS) sequencing technique. The detached leaf assay was conducted to assess the disease severity of Fusarium phytopathogens against detached coffee leaves. Moreover, dual culture assay was utilized to assess the antagonistic activity of D. caatingaensis.

Results and conclusion

Fusarium oxysporum was found to be the most frequent isolated strain followed by F. solani, F. proliferatum and F. verticillioides strains. Fusarium proliferatum strain was found to be the most severe strain whereas F. solani strain showed the lowest disease severity. On the other hand, propiconazole fungicide was tested for its efficiency against Fusarium pathogens using food poisoning technique, showing that F. oxysporum strain 1 of accession number OP955665 was the most sensitive strain. However, F. proliferatum, F. oxysporum st. 2 (OP959851) and F. solani strains showed no significant response when the propiconazole concentration increase from 150 to 200 ppm. Scanning electron microscope proved the potent antagonistic activity of D. caatingaensis against F. proliferatum and F. oxysporum OP959874 strains through mycoparasitic modes of action as coiling, appressorium formation resulting in complete lysis of fungal mycelium. Accordingly, the current investigation provides the first surveillance data about Fusarium strains associated with coffee plants and also the utilization of D. caatingaensis as a potential biocontrol agent for effective management of Fusarium phytopathogens, avoiding the incidence of fungal resistance to fungicides and the harmful effects of commercial fungicides for sustainable cultivation of coffee in Saudi Arabia.

Pure and Fe-doped TiO₂ nanoparticles were synthesized through green synthesis route for wastewater remediation application. Pure and Fe-doped TiO₂ nanoparticles were further characterised through various techniques like XRD, SEM, and EDS. The XRD patterns indicate pure anatase phase with space group I 41/a m d through the Rietveld refinement. The average crystalline size of Fe-doped TiO₂ nanoparticles decreases with the increment in the concentration of doping. The high agglomeration of pure and Fe-doped TiO₂ nanoparticles is observed through SEM. EDS analysis conforms the presence of Fe, Ti, and O elements in the nanoparticles. The photo catalytic activities of pure and Fe-doped TiO₂ under ultraviolet (UV) light with different concentration were investigated. The dissolved oxygen in the water increases with the increment of Fe doping and time of exposer of UV light.

The traditional cubic B-spline method offers limited local control over the curve solution. Adjusting the position of a control point affects the entire curve, making it challenging to make localized changes, e.g., smoothness. Moreover, the basis functions vanish on one side by the cubic B-spline method near the end conditions where the initial and boundary conditions are applied. To address these limitations, this research proposes a new basis by including a free parameter $\gamma$ with the purpose of modifying the weights of nearby control points. This free parameter $\gamma$ can influence the curve’s behavior in specific regions as well as the entire curve. This modification of the cubic B-spline method was used to approximate the second-order derivative at each collocation point. The convergence test showed that the proposed method was second-order convergent. Numerical examples of ordinary differential equations were used with different step values to evaluate the accuracy of the proposed method. The findings persistently indicated that the proposed technique provided better error estimates as compared to the other methods discussed in the literatures.